Table 2. ANOVA for the third factorial design.

Source of

variation

Sum of square

Degrees of

freedom

Mean square

F-ratio

(model significance)

Regression

24.84

4

6.21

28.53^a

Residual

2.61

12

0.28

Lack of fit

2.55

10

0.25

Pure error

0.07

2

0.03

Total

27.45

16